inDocker property

Implementation

static bool get inDocker {
  if (_inDocker == null) {
    _inDocker = false;

    /// Buildx no longer creates the /.dockerenv so we need
    /// to check cgroups.
    const pathToCgroup = '/proc/1/cgroup';

    if (exists(pathToCgroup)) {
      final lines = read(pathToCgroup).toList();
      for (final line in lines) {
        if (line.contains(':docker:')) {
          _inDocker = true;
          break;
        }
      }
    }
    if (_inDocker == false) {
      /// At some point we should remove the ./dockerenv test
      /// but I'm uncertain if the cgroup method works on older containers.
      _inDocker = exists('/.dockerenv');
    }
  }

  return _inDocker!;
}